The stamps aren't fake. Visa was issued by Thai immigration, so you certainly won't have any issues obtaining a tourist visa.
However, you might get questioned coming back into Thailand on a tourist visa after spending so long in the country.
There was a general crackdown on that before covid, and I would imagine that's still the case.
I arrived back last month on a TV, after being out of the country for 18 months, and 2 immigration officers scoured through my history on their computer. They asked why I was here and for a contact in Thailand. They were perfectly polite, but it was a bit unnerving.
Make sure you've got your story straight.